Manufacture of electric discharge tubes



Feb. 11, 1936. AG. PEARCE MANUFACTURE OF ELECTRIC DISCHARE TUBES Filed July 19, 1934 BY 2? 4mm,

ATTO NEY I Patented Feb. 11, 1936 2,030,892 7 MANUFACTURE OF ELECTRIC DISCHARGE TUBES Arthur George Pearce, Middlesex, England, slsignor to General Electric Company, a corporation of New York Application July is, 1934, Serial No. 738.082 is Great Britain July as. 1983 Z Cid. (Cl. 178 122) This invention relates to the manufacture of electric discharge tubes, and more particularly lnous electric discharge tubes, of the type in. which a discharge tube proper is enclosed in en outer envelope, which may be evacuated.

A perticular object of the invention is to pro vide a novel means of supporting a gaseous discharge device wit an outer Jacket. Other objects and advantages of the invention will tippear from the following detailed description or from the drawing.

The invention consists in the new and novel combination of elements hereinafter set forth end clnixned. v

In lamps which must operate at a relatively high temperature the discharge tube has hitherto usuelly been supported in an outer envelope by means of rings attached to the long-in wires. This form of construction is mechanically week end as a result the tubes are apt to be damaged in transport. The elternative of supporting the discharge tube by members bearing on its body has not been edopted because such supports, being in contest with the body, produce local cool= ing, which it is one of the objects of the en= velope to prevent. l have now round that this dimculty can be overcome by means of supporting members of novel design.

According to the invention, en electric discharge lamp of the type specified comprises a plurality of annuler metal members supporting the discharge tube proper in the outer envelope, eech annular member bearing on the body or the discharge tube only at a plurality of isolated places, the sum of whose lengths measured along the circ .1 erence of the discharge tube is much less than the length of that circumference. Preferaoly the number of annular members is two.

e number of isolated places of contact is pref- 0 erably three or more. The thickness of the metal of the members and the width of the annulus should also be es all as is consistent with me= chemical strength, in order to decrease heat conductionirom the points of contact.

One embodiment of the invention is shown by way of example in the accompanying drawing in which Figure 1 is an elevation of the complete lamp;

Figure 2 a section perpendicular to its axis through one of the annular members.

Figure 3 is a similar view to that of Figure 2 showing a modification of the structure 01' Fig- L, urea i and 2, and

55 Figures 4 and 5 are" fragmentary elevations showing further modiflcatio of the structure of Figure i.

In this with particular reference to Figs. 1, 2 and 3, l is the discharge tube proper, 2 the outer envelope; 8, t are the annular sup- 5 porting members of sheet nickel about 0.2 mm. thick; their width .is about 3 They are spoced longitudinally by the wire it which runs along the whole length of the tube and connects the electrode 9 to the lending-in wire 10 through the pinch seel at the other end. The supporting members ii, 3 may be connected di rectly to ill, as shown in Figs. 1 and 2, or they may he fixedto insulating tube ii surrounding and carried by iii, as shown in Fig. 3. In 15 some cases, where the direct connection may lead to blackening of the tube, this alternative con= struction is preferable.

As shown in Figure 2 each member 8, 3 consists of a corrugated portion (1 and arcuate por- 2o tions d. Some of the or apices of the corru-= getions bear on the tube i; the number of those that bear on it will adjust itself to be at least three and generally no more than three. The arcuate portions .6, which bear against the outer 2s envelope, are each etteched at one end to the outer apex of one of the corrugations, but are free at their other ends; their object is to ire I the ember more resilient and to allow it to adapt itself to envelopes of slightly diflerent diameters 30 and also to ellow the corrugated portion t to adapt itself to tubes of slightly different diam= eters.

The wire l is part of a starting device in which n conductor at the potential of one electrode is 35 brought into the neighborhood of the other. If the supporting member 8 is in the neighborhood of the electrode t and connected electrically by the wire it to the remote electrode ll, as sho in Figs. 1 and 2, this member by itself may-act as one end of the conductor in a starting device of this kind. It is generally advisable, however, to supplement this member s by the thin wire l, in electrical connection with 8 t and It, wrapped in a single spiral turn around the greater part of the length of the tube and in several turns of a close spiral near the member 3 this arrangement is shown in the drawing. If the supporting member '3 is insulated from the re- 50 mote electrode, as in Fig. 3, the wire i will be necessary, of course, if a starting device of this kind is required.

Alternative forms of supporting member according to the invention are shown in Flames 15 d and 5. In each of these figures only one supporting member and the parts of the inner tube i and an outer envelope 2 on which it bears are shown; the remainder of the device being as shown in Fig. i.

In Figure i the supporting member is an annular wire helix; it. In Figure 5 it is an annular wire zig-zag it, the zig-zag being distorted from a plane so that the central portions bear on the outer envelope and the edges on theinner tube.

The supporting members i3 and M do not generally require to be held in position longitudinally, although they may be attached to the wire it if desired.

While I have described my invention by reference to certain embodiments thereof it is to be understood that various changes, omissions and substitutions, within the scope of the appended claims, may be made therein without departing from the spirit thereof.

What I claim as new and desire to secure by Letters Patent oi the United States is:-

- 1. An electric gaseous discharge device comprising a. sealed envelope containing a gaseous atmosphere and having electrodes sealed therein, an enclosing heat-conserving jacket for said envelope, and means to support said envelope.

concentrically within said jacket, said means comprising a metal member which surrounds said envelope and makes contact-therewith only at a plurality of isolated places.

2. An electric gaseous discharge device comprising a sealed envelope containing a gaseous atmosphere and having electrodes sealed therein, an enclosing heat-conserving jacket for said envelope, and means to support said envelope concentrically within said jacket, said means' comprising a corrugated metal member which encircles said envelope and makes contact therewith only at theinner apices of the corrugations.

3. An electric gaseous discharge device comprising a sealed envelope containing a gaseous atmosphere and having electrodes sealed therein, an enclosing heat-conserving jacket for said envelope, and means to support said envelope concentrically within said jacket, said means comprising a corrugated metal member which encircles said envelope and makes contact therewith only at isolated points, said members hav ing resilient metal strips aflixed thereto which bear upon the inner suriaoe of said jacket.

4. An electric gaseous discharge device comprising a sealed envelope containing a gaseous atmosphere and having electrodes sealed therein, an enclosing heat-conserving jacket for said envelope, and means to support said envelope concentrically within said jacket, said means comprising a wire helix which surrounds said envelope and makes contact therewith only at separated points.

5. An electric gaseous discharge device comprising a sealed envelope containing a gaseous atmosphere and having electrodes sealed therein, an enclosing heat-conserving jacket for said envelope, and. means to support said envelope concentrically within said jacket, said means comprising a wire which forms a succession of apices which make contact alternately with said envelope and said jacket, successive points of contact with one of said bodies lying on opposite sides of a plane which passes through the points or contact with the other.

6. An electric gaseous discharge device comprising a sealed envelope containingv a gaseous atmosphere and having electrodes sealed thereiii in, an enclosing heat-conserving jacket for said envelope, and means to supportsaid envelope concentrically within said jacket, said means comprising a metal member which surrounds said envelope and makes contact therewith only at isolated points, said member being attached to the lead to one of said inleads.

7. An electric gaseous discharge device comprising a sealed envelope containing a gaseous atmosphere and having electrodes sealed therein, an enclosing heat-conserving jacket for said envelope, and means to support said envelope concentrically within said jacket, said means comprising a metal member which surrounds said envelope and makes contact therewith only at isolated points, said member being attached to the lead to one of said-inle'ads but insulated therefrom.

ARTHUR GEORGE PEARCE. 

